반응 #2075721

반응 방정식

1-chloro-3-fluoro-2-(1-fluoroethyl)benzene

n-butyllithium

diisopropylamine

2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

→

title compound

수율 94.0%

2-(4-Chloro-2-fluoro-3-(1-fluoroethyl)phenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

수율 94.0%

용매

THF

hydrochloric acid

tetrahydrofuran THF

반응 조건

후처리

1. 1
   온도warmed to 0° C. for 20 m
2. 2
   온도cooled back to −78° C. for 20 m
3. 3
   기타at −78° C.
4. 4
   workup.STIRRINGThe resulting dark brown solution was stirred at −78° C. for 2 h
5. 5
   온도the brown solution was slowly warmed to 23° C. over 20 h
6. 6
   추출extracted with dichloromethane three times
7. 7
   기타The combined organic layers were dried
8. 8
   여과filtered
9. 9
   농축concentrated by rotary evaporation

실험 절차

A 2.5 M solution of n-butyllithium (13 mL, 33 mmol) was added to a stirred solution of diisopropylamine (5.0 mL, 35 mmol) in tetrahydrofuran THF (50 mL) at −78° C. The resulting colorless solution was stirred at −78° C. for 20 m, warmed to 0° C. for 20 m, and then cooled back to −78° C. for 20 m. A solution of 1-chloro-3-fluoro-2-(1-fluoroethyl)benzene (4.8 g, 27 mmol, 1.0 equiv) in THF (20 mL) at −78° C. was transferred to the base solution via cannula. The resulting dark brown solution was stirred at −78° C. for 2 h. 2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (8.3 mL, 41 mmol, 1.5 equiv) was added and the brown solution was slowly warmed to 23° C. over 20 h. The reaction mixture was diluted with 0.1M hydrochloric acid (300 mL) and extracted with dichloromethane three times. The combined organic layers were dried, filtered and concentrated by rotary evaporation to afford the title compound as a brown oil that solidified into a semi-solid upon standing (7.7 g, 94% yield). 1H NMR (300 MHz, CDCl3) δ 7.62 (m, 1H), 7.17 (m, 1H), 6.13 (dq, 1H, J=6, 46 Hz), 1.75 (ddd, 3H, J=1, 7, 23 Hz), 1.36 (s, 12 H).

출처